<template>
  <div class="todo-footer">
    <label>
      <input type="checkbox" v-model="checkAll"/>
    </label>
    <span>
          <span>已完成{{completeCount}}</span> / 全部{{totalCount}}
        </span>
    <button class="btn btn-danger" v-show="completeCount" @click="clearAllCompleted">清除已完成任务</button>
  </div>
</template>

<script>
  import {mapGetters,mapActions} from 'vuex'

  export default {

    computed: {
      ...mapGetters(['totalCount','completeCount']),

      //计算属性高级
      checkAll: {
        //回调函数 当需要读取当前属性值时回调，根据相关的数据计算并返回当前属性的值
        get () {
          return this.$store.getters.isAllSelect
        },

        // 回调函数，监视当前属性值的变化，当属性值发生改变时回调，更新相关的属性数据
        set (value) { //value是当前checkbox最新的值
          //this.selectAllTodos(value)
          this.$store.dispatch('selectAllTodos', value)
        }
      }
    },

    methods: {
      ...mapActions(['clearAllCompleted'])
    }
  }
</script>

<style scoped>

  .todo-footer {
    height: 40px;
    line-height: 40px;
    padding-left: 6px;
    margin-top: 5px;
  }

  .todo-footer label {
    display: inline-block;
    margin-right: 20px;
    cursor: pointer;
  }

  .todo-footer label input {
    position: relative;
    top: -1px;
    vertical-align: middle;
    margin-right: 5px;
  }

  .todo-footer button {
    float: right;
    margin-top: 5px;
  }
</style>
